A myc tag is a polypeptide protein tag derived from the c-myc gene product that can be added to a protein using recombinant DNA technology. It can be used for affinity chromatography, then used to separate recombinant, overexpressed protein from wild type protein expressed by the host organism. It can also be used in the isolation of protein complexes with multiple subunits.

A myc tag can be used in many different assays that require recognition by an antibody. If there is no antibody against the studied protein, adding a myc-tag allows one to follow the protein with an antibody against the Myc epitope. Examples are cellular localization studies by immunofluorescence or detection by Western blotting.

The peptide sequence of the myc-tag is: N-EQKLISEEDL-C (1202 Da). It can be fused to the C-terminus and the N-terminus of a protein. It is advisable not to fuse the tag directly behind the signal peptide of a secretory protein, since it can interfere with translocation into the secretory pathway.

CCL11 or chemokine (C-C motif) ligand 11 is a member of the chemokine (C-C motif) ligand family. Chemokin (C-C motif) ligand 11 is a member of the chemokine family. There are four members of the chemokine family: C-C kemokines, C kemokines, CXC kemokines and CX3C kemokines. The C-C kemokines have two cysteines nearby the amino terminus. There have been at least 27 distinct members of this subgroup reported for mammals, called C-C chemokine ligands (CCL)-1 to 28. Chemokines are a family of small chemotactic cytokines, or proteins secreted by cells. They share the same structure similarities such as small size, and the presence of four cysteine residues in conserved locations in order to form their 3-dimensional shape. Some of the chemokines are considered pro-inflammatory which can be induced to recruit cells of the immune system to a site of infection during an immune response, while others are considered homeostatic and are implied in controlling the migration of cells during normal processes of tissue maintenance and development. CCL11 is implicated in allergic responses through selectively recruiting eosinophils by inducing their chemotaxis. The effects of CCL11 are mediated by its binding to chemokine receptor. Increased CCL11 levels in blood plasma are associated with aging in mice.